US20080003100A1 - Methods and apparatus to facilitate sealing in a turbine - Google Patents
Methods and apparatus to facilitate sealing in a turbine Download PDFInfo
- Publication number
- US20080003100A1 US20080003100A1 US11/427,866 US42786606A US2008003100A1 US 20080003100 A1 US20080003100 A1 US 20080003100A1 US 42786606 A US42786606 A US 42786606A US 2008003100 A1 US2008003100 A1 US 2008003100A1
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- United States
- Prior art keywords
- biasing mechanism
- seal ring
- accordance
- seal
- recess
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D11/00—Preventing or minimising internal leakage of working-fluid, e.g. between stages
- F01D11/02—Preventing or minimising internal leakage of working-fluid, e.g. between stages by non-contact sealings, e.g. of labyrinth type
- F01D11/025—Seal clearance control; Floating assembly; Adaptation means to differential thermal dilatations
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D11/00—Preventing or minimising internal leakage of working-fluid, e.g. between stages
- F01D11/08—Preventing or minimising internal leakage of working-fluid, e.g. between stages for sealing space between rotor blade tips and stator
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D11/00—Preventing or minimising internal leakage of working-fluid, e.g. between stages
- F01D11/08—Preventing or minimising internal leakage of working-fluid, e.g. between stages for sealing space between rotor blade tips and stator
- F01D11/12—Preventing or minimising internal leakage of working-fluid, e.g. between stages for sealing space between rotor blade tips and stator using a rubstrip, e.g. erodible. deformable or resiliently-biased part
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
- F02C7/00—Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for jet-propulsion plants
- F02C7/28—Arrangement of seals
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2220/00—Application
- F05D2220/30—Application in turbines
- F05D2220/31—Application in turbines in steam turbines
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2250/00—Geometry
- F05D2250/10—Two-dimensional
- F05D2250/18—Two-dimensional patterned
- F05D2250/182—Two-dimensional patterned crenellated, notched
Definitions
- This invention relates generally to turbines, and, more particularly, to seal ring assemblies for use with turbines.
- At least some known seal assemblies used with turbines are biased open by a spring coupled thereto. More specifically, the spring induces a radially outward biasing force against a seal ring that increases a diameter of the seal ring. As pressure is increased within the turbine, the biasing force induced by the spring must be overcome to decrease the diameter of the seal ring to facilitate preventing steam flow through the seal assembly within the turbine. Accordingly, in such sealing assemblies, radial inward travel of the seal ring is generally delayed until pre-determined operating conditions for the turbine are attained.
- At least some known seal assembly springs may be installed in the field during final assembly of the turbine. Specifically, the springs may be temporarily positioned against the seal ring using re-roundable dowels which do not provide positive retention and only retain the spring after the seal ring is installed in the packing assembly. As such the spring may fall out or be deformed during installation of the seal ring. Moreover, the seal ring can not be shipped with the spring pre-installed. Accordingly, such seal ring/spring assemblies may increase installation time, decrease quality, and increase overall costs associated with installation of the seal assembly.
- a method of assembling a seal assembly for a turbine engine includes providing a seal ring having an arcuate inner ring portion, an arcuate outer ring portion, and a neck portion extending therebetween, and forming at least one recess within at least one of the outer ring portion and the neck portion.
- the method also includes extending a biasing mechanism across the seal ring such that the biasing mechanism is positively retained within the at least one recess.
- a seal assembly for a turbine engine wherein the seal assembly includes a seal ring comprising an arcuate inner ring portion, an arcuate outer ring portion, and a neck portion extending therebetween.
- the seal assembly also includes at least one recess formed within at least one of the seal ring outer ring portion and the seal ring neck portion, and a biasing mechanism extending chordially across the seal ring and retained within the at least one recess.
- a turbine engine configured to reduce steam leakage within the turbine engine.
- the seal assembly includes a seal ring comprising an arcuate inner ring portion, an arcuate outer ring portion, and a neck portion extending therebetween.
- the seal assembly also includes at least one recess formed within at least one of the seal ring outer ring portion and the seal ring neck portion, and a biasing mechanism extending chordially across the seal ring and retained within the at least one recess.
- FIG. 1 is a schematic illustration of an exemplary opposed flow High Pressure (HP)/Intermediate Pressure (IP) steam turbine;
- FIG. 2 is an enlarged schematic illustration of a turbine nozzle diaphragm and a packing casing that may be used with the steam turbine shown in FIG. 1 ;
- FIG. 3 is an exemplary embodiment of a labyrinth seal assembly that may be used with the steam turbine shown in FIG. 1 ;
- FIG. 4 is an exemplary embodiment of a seal ring that may be used with the labyrinth seal assembly shown in FIG. 3 ;
- FIG. 5 is an alternative embodiment of the seal ring shown in FIG. 4 ;
- FIG. 6 is another embodiment of the seal ring shown in FIG. 4 ;
- FIG. 7 is a view of a biasing mechanism that may be used with the labyrinth seal assembly shown in FIG. 3 ;
- FIG. 8 is a view of the biasing mechanism shown in FIG. 7 and coupled within the seal ring shown in FIG. 6 ;
- FIG. 9 is a view of the biasing mechanism shown in FIG. 7 and coupled within an alternative embodiment of the seal ring shown in FIG. 4 ;
- FIG. 10 is an illustration of the biasing mechanism shown in FIG. 7 and including indicia indicative of a contact point
- FIG. 11 is yet another embodiment of the seal ring shown in FIG. 4 and including a retaining pin
- FIG. 12 is a front view of an another embodiment of the seal ring shown in FIG. 4 ;
- FIG. 13 is a side view of the seal ring shown in FIG. 12 ;
- FIG. 14 is a front view of yet another embodiment of the seal ring shown in FIG. 4 ;
- FIG. 15 is a side view of the seal ring shown in FIG. 14 ;
- FIG. 16 is another embodiment of the seal ring shown in FIG. 4 ;
- FIG. 17 is a view of a biasing mechanism that may be used with seal ring shown in FIG. 16 .
- FIG. 1 is a schematic illustration of an exemplary opposed-flow steam turbine 10 including a high pressure (HP) section 12 and an intermediate pressure (IP) section 14 .
- An outer shell or casing 16 is divided axially into upper and lower half sections 13 and 15 , respectively, and spans both HP section 12 and IP section 14 .
- a central section 18 of shell 16 includes a high pressure steam inlet 20 and an intermediate pressure steam inlet 22 .
- HP section 12 and IP section 14 are arranged in a single bearing span supported by journal bearings 26 and 28 .
- a steam seal unit 30 and 32 is located inboard of each journal bearing 26 and 28 , respectively.
- An annular section divider 42 extends radially inwardly from central section 18 towards a rotor shaft 60 that extends between HP section 12 and IP section 14 . More specifically, divider 42 extends circumferentially around a portion of rotor shaft 60 between a first HP section nozzle 46 and a first IP section nozzle 48 .
- high pressure steam inlet 20 receives high pressure/high temperature steam from a steam source, for example, a power boiler (not shown). Steam is routed through HP section 12 wherein work is extracted from the steam to rotate rotor shaft 60 . The steam exits HP section 12 and is returned to the boiler wherein it is reheated. Reheated steam is then routed to intermediate pressure steam inlet 22 and returned to IP section 14 at a reduced pressure than steam entering BP section 12 , but at a temperature that is approximately equal to the temperature of steam entering HP section 12 . Accordingly, an operating pressure within HP section 12 is higher than an operating pressure within IP section 14 , such that steam within HP section 12 tends to flow towards IP section 14 through leakage paths that may develop between HP section 12 and IP section 14 .
- FIG. 2 is an enlarged schematic illustration of an exemplary turbine nozzle diaphragm 70 and a packing casing 72 that may be used with turbine 10 .
- nozzle diaphragm 70 is a first stage diaphragm used with high pressure turbine 12 .
- packing casing 72 includes a plurality of labyrinth seal assemblies 100 that facilitate reducing leakage from HP section 12 to IP section 14 along rotor shaft 60 .
- Labyrinth seal assemblies 100 include longitudinally spaced-apart rows of teeth 104 attached to a seal ring 102 that facilitate sealing against operating pressure differentials that may be present in a steam turbine such as turbine 10 .
- steam at higher pressure in HP section 12 tends to leak through a steam path defined between first stage nozzle diaphragm 70 and packing casing 72 to IP section 14 , an area at a lower operating pressure.
- high pressure steam is admitted to HP section 12 at approximately 1800 pounds per square inch absolute (psia)
- reheat steam is admitted to IP section 14 at between approximately 300-400 psia. Accordingly, a relatively large pressure drop across packing casing 72 may cause steam to leak around packing casing 72 along rotor shaft 60 resulting in a reduction in steam turbine efficiency.
- FIG. 3 is an exemplary embodiment of a labyrinth seal assembly 100 that may be used with turbine 10 .
- a labyrinth seal assembly 100 that may be used with turbine 10 .
- FIG. 3 only a portion of rotor shaft 60 and a portion of casing 72 are illustrated.
- a single seal ring 102 is illustrated, several such rings could be arranged in series as shown in FIG. 2 .
- labyrinth seal assemblies 100 are used to facilitate sealing in other areas of turbine 10 .
- Seal ring 102 includes a plurality of teeth 104 positioned in opposition to a plurality of rotor shaft circumferential projections 105 extending outward from rotor shaft 60 .
- each circumferential projection 105 includes radially outer rotor surfaces 107 positioned between a plurality of radially inner rotor surfaces 109 .
- a positive force may force fluid flow between the multiple restrictions formed by a clearance area 110 defined between teeth 104 and rotor shaft 60 . More specifically, the combination of clearance area 110 , the number, and relative sharpness, of teeth 104 , the number of rotor shaft circumferential projections 105 , and the operating conditions, including pressure and density, are factors that determine the amount of leakage flow.
- rotor portion 60 does not include teeth 105 or surfaces 109 , but rather, is substantially planar.
- seal ring 102 does not include a serpentine path with the rotor teeth.
- seal ring 102 may include a brush seal or any other suitable sealing mechanism.
- each seal ring 102 is retained in a casing groove 112 defined in casing 72 .
- each seal ring 102 includes a plurality of seal ring segments (not shown in FIG. 3 ) that may be positioned within casing groove 112 to facilitate ease of assembly or disassembly of casing 72 .
- a system of springs (not shown in FIG. 3 ) induces a force that will tend to enlarge a diameter of seal ring 102 and a second system of springs (not shown in FIG. 3 ) may be used to counter the force induced by the weight of seal ring 102 .
- Each seal ring 102 includes an inner ring portion 114 having teeth 104 extending from a radially inner surface 116 , and a radially outer surface 130 that facilitates controlling clearance area 110 by contacting a radial surface 118 of casing 72 .
- Each seal ring 102 also includes an outer ring portion 120 that is positioned within casing groove 112 .
- Outer ring portion 120 includes an inner circumferential surface 122 and an opposite radially outer surface 131 .
- Inner circumferential surface 122 contacts an outer surface 126 of a casing groove shoulder 124 such that radial inward movement of seal ring 102 is limited.
- Seal ring 102 also includes a neck portion 128 extending between seal ring inner ring portion 114 and seal ring outer ring portion 120 .
- Casing groove shoulder 124 interacts with seal ring neck portion 128 to axially locate each seal ring 102 .
- Seal ring neck portion 128 includes a contact pressure surface 132 that contacts casing groove shoulder 124 .
- One steam flow path through labyrinth seal assembly 100 is defined from high pressure region 106 to low pressure region 108 through clearance area 110 and between teeth 104 and rotor shaft surfaces 107 and 109 .
- Steam flow is modulated as a function of radial positioning of seal ring 102 .
- seal ring 102 moves radially outward, the overall size of clearance area 110 increases and steam flow through clearance area 110 increases.
- clearance area 110 decreases and steam flow through clearance area 110 decreases.
- a second steam flow path is defined from high pressure annular space 134 to low pressure annular space 136 through casing groove 112 .
- Steam at a higher pressure may flow from annular space 134 through an annular opening 140 defined between casing groove shoulder 124 and seal ring neck portion 128 .
- Steam is channeled through opening 140 to a high pressure region 142 defined between casing groove shoulder outer surface 126 and seal ring outer ring portion ring circumferential surface 122 before entering a casing groove high pressure portion 144 defined by the casing 72 and seal ring outer ring portion 120 .
- seal ring 102 Radially outward travel of seal ring 102 is limited when seal ring outer surface 130 , or any portion thereof, contacts casing radial surface 118 . This position is referred to as the fully retracted position. Radially inward travel of seal ring 102 is limited when seal ring surface 122 contacts casing groove shoulder surface 126 . This position is referred to as the fully inserted position. Sufficient space to accommodate expected transient misalignments of rotor shaft 60 and casing 72 , without incurring damage to teeth 104 , is provided for.
- seal ring 102 At low or no load operating conditions, the weight of seal ring 102 , the confining limits of casing 72 , frictional forces, and the forces of a plurality of biasing spring systems (not shown on FIG. 3 ) act on seal ring 102 .
- the overall effect is that seal ring 102 is biased to a diameter as limited by the radially outward limit of travel of seal ring 102 .
- Internal pressures throughout the turbine 10 are substantially proportional to load. As load and steam mass flow are each increased, local pressures increase in a substantially linear fashion. This relationship can be used to determine desired positions of seal ring 102 at pre-determined turbine operating conditions. For example, as steam flow to turbine 10 is increased, steam pressure in annular space 134 and in casing groove 112 is likewise increased. The increased steam pressure exerts a radially inward force to seal ring 102 that is substantially carried by seal ring outer surfaces 130 and 131 .
- the increased steam pressure in high pressure region 106 induces increased steam flow via casing groove 112 through annular space 134 , annular opening 140 , shoulder region 142 , casing groove high pressure portion 144 , casing groove radially outer portion 148 , casing groove low pressure portion 150 , shoulder region 152 , and annular opening 154 into annular region 136 .
- the increased steam pressure in high pressure region 106 also induces increased pressures in the path defined from annular space 134 to annular space 136 via casing groove 112 as described above.
- the pressures in each subsequent region of the path are less than the regions preceding them.
- the steam pressure in casing groove low pressure portion 150 is less than the steam pressure in casing groove high pressure portion 144 .
- This pressure differential induces an increased force to the right on seal ring inner ring portion 114 , seal ring neck portion 128 and seal ring outer ring portion 120 .
- the increased forces on these surfaces causes seal ring 102 to move axially toward the low pressure region 108 until seal ring neck contact pressure surface 132 contacts casing groove shoulder 124 .
- seal ring 102 When fully inserted steam flow from high pressure annular space 134 to low pressure annular space 136 via casing groove 112 is substantially prevented by seal ring 102 .
- the condition illustrated above causes steam pressure to induce an increased radially inward force to surfaces 130 and 131 as described above.
- the increased steam pressure also induces an increased radially inward force to seal ring 102 to overcome the previously discussed frictional forces and plurality of biasing spring sub-systems (not shown) forces.
- seal ring 102 and casing groove 112 are selected to facilitate optimizing the clearance 110 defined between teeth 104 and rotor shaft 60 surface for loaded, steady state operation.
- FIG. 4 is an exemplary embodiment of a seal ring 200 that may be used with labyrinth seal assembly 100
- Seal ring 200 includes an outer ring portion 202 , an inner ring portion 204 , and a neck portion 206 extending therebetween.
- Seal ring 200 also includes a biasing mechanism 208 retained within a cavity 210 .
- biasing mechanism 208 is a spring.
- cavity 210 is formed within outer ring portion 202 and includes an arcuate top wall 212 and a pair of opposing sidewalls 214 .
- cavity 210 may be formed in seal ring neck portion 206 , Biasing mechanism 208 extends between sidewalls 214 .
- biasing mechanism 208 is positively retained within cavity 210 in a friction fit created between biasing mechanism ends 216 and 220 and side walls 214 .
- biasing mechanism 208 may be retained within cavity 210 by any one oft but not limited to, a tack weld, a screw, a pin, and/or glue.
- FIG. 5 is an alternative embodiment of seal ring 200 wherein sidewalls 214 of cavity 210 are angled. Specifically each side wall 218 and 222 extends radially inward from top wall 212 such that sidewalls 218 and 222 are angled toward on another. As such a radially outward portion 230 of cavity 210 has a longer arcuate length L 1 than an arcuate length L 2 of a radially inward portion 232 of cavity 210 . Biasing mechanism 208 is positively retained within radially outward portion 230 by sidewalls 218 and 222 .
- each sidewall 218 and 222 provides an interference fit for biasing mechanism 208 such that biasing mechanism 208 is prevented from moving radially inward toward radially inward portion 232 .
- biasing mechanism 208 is positively retained within cavity 210 in a friction fit created between biasing mechanism ends 216 and 220 and sidewalls 214 .
- biasing mechanism 208 may be retained within cavity 210 by any one of, but not limited to, a tack weld, a screw, a pin, and/or glue.
- FIG. 6 is another embodiment of seal ring 200 wherein cavity 210 includes a pair of notches 240 .
- each notch 240 is formed within one of sidewalls 214 within cavity radially outward portion 230 . More specifically, a first notch 242 is formed within first sidewall 218 and a second notch 244 is formed within second sidewall 222 .
- Notches 240 are each sized to retain an end of biasing mechanism 208 . Specifically, first notch 242 retains biasing mechanism first end 216 , and second notch 244 retains biasing mechanism second end 220 .
- biasing mechanism 208 is positively retained within cavity 210 in a friction fit created between biasing mechanism ends 216 and 220 and notches 242 and 244 , respectively.
- biasing mechanism 208 may be retained within notches 242 and 244 by any one of, but not limited to, a tack weld, a screw, a pin, and/or glue.
- FIG. 7 is a view of biasing mechanism 208 including a tab 250 extending axially from each biasing mechanism end 216 and 220 ; and FIG. 8 is a view of biasing mechanism 208 having tabs 250 and coupled within seal ring 200 shown in FIG. 6 .
- Tabs 250 are used to provide additional length to biasing mechanism 208 and to provide a positive engagement of notches 242 and 244 .
- Biasing mechanism 208 is positively retained within cavity 210 in a friction fit created between tabs 250 and notches 242 and 244 .
- tabs 250 may be retained within notches 242 and 244 by any one of, but not limited to, a tack weld, a screw, a pin, and/or glue.
- FIG. 9 is a view of biasing mechanism 208 having tabs 250 and coupled within an alternative embodiment of seal ring 200 .
- arcuate top wall 212 of cavity 210 includes a linear portion 260 extending from each notch 242 and 244 .
- Each linear portion 260 is configured to engage biasing mechanism 208 such that bending forces within biasing mechanism 208 are distributed across the entire length of biasing mechanism 208 rather than being isolated at tabs 250 .
- FIG. 10 is an illustration of locations 270 where linear portion 260 contacts biasing mechanism 208 .
- biasing mechanism 208 is positively retained within cavity 210 in a friction fit created between tabs 250 and notches 242 and 244 .
- tabs 250 may be retained within notches 242 and 244 by any one of, but not limited to, a tack weld, a screw, a pin, and/or glue.
- FIG. 11 is a view of seal ring 200 including a pin 280 used to retain biasing mechanism 208 within cavity 210 .
- biasing mechanism 208 includes tabs 250 engaged with notches 240 .
- Pin 280 is inserted through outer ring portion 206 such that pin 280 traverses notch 240 to facilitate retaining biasing mechanism 208 within cavity 210 .
- pin 280 traverses notch 240 such that tab 250 is retained between pin 280 and a back surface 282 of cavity 210 .
- the illustrated embodiment includes one pin 280 retaining one tab 250 .
- the second tab 250 is retained within notch 240 by one of friction, a tack weld, or glue.
- two pins 280 are inserted through outer ring portion 202 such that both tabs 250 are retained between pins 280 and cavity back surface 282 .
- tabs 250 include an aperture therethrough and at least one pin 280 is inserted through the aperture of at least one tab 250 as pin 280 traverses notch 240 .
- biasing mechanism 208 may not include tabs 250 . Accordingly, at least one pin 280 is inserted through at least one end of biasing mechanism 208 as pin 280 traverses notch 240 .
- pin 280 may be a screw.
- FIG. 12 is a front view of an alternative embodiment of seal ring 200 having cavity 290 formed entirely within outer ring portion 202 ; and FIG. 13 is a side view of seal ring 200 shown in FIG. 12 .
- cavity 290 is formed within outer ring portion 202 such that cavity 290 includes an arcuate top wall 292 , a front wall 294 , a back wall 296 , and two opposing sidewalls 298 .
- Sidewalls 298 each include a notch 300 formed therein. Notches 300 are configured to retain ends 216 and 220 of biasing mechanism 208 such that biasing mechanism 208 extends across cavity 290 .
- Biasing mechanism 208 is positively retained within cavity 290 in a friction fit created between biasing mechanism ends 216 and 220 and notches 300 , front wall 294 , and back wall 296 .
- biasing mechanism 208 may be positively retained within cavity 290 by any one of, but not limited to, a tack weld, a pin, a screw, and/or glue.
- biasing mechanism 208 may include tabs 250 .
- sidewalls 298 of cavity 290 may be shaped similar to sidewalls 214 shown in FIG. 4 or FIG. 5 .
- FIG. 14 is a front view of yet another embodiment of seal ring 200 ; and FIG. 15 is a side view of seal ring 200 shown in FIG. 14 .
- seal ring 200 does not include a cavity formed within outer ring portion 206 . Rather, this embodiment includes a pair of threaded apertures 310 formed within neck portion 206 of seal ring 200 . Each threaded aperture 310 is configured to retain a screw 314 therein.
- Biasing mechanism 208 includes a pair of bent tabs 316 extending therefrom. Specifically, a first bent tab 318 extends from biasing mechanism first end 216 , and a second bent tab 320 extends from biasing mechanism second end 220 .
- Each bent tab 316 includes a first member 322 coupled to biasing mechanism 208 , and a second member 324 extending from first member 322 . Second member 324 includes an aperture extending therethrough.
- Biasing mechanism 208 is positioned against neck portion 206 such that it is radially inward from outer ring portion 202 . Second member 324 of each bent tab 316 is aligned with threaded aperture 310 such that screw 314 is received through the aperture in second member 324 and extends through threaded aperture 310 . As such, biasing mechanism 208 extends across neck portion 206 and is positively retained by screws 314 .
- FIG. 16 is another embodiment of seal ring 200 ; and FIG. 17 is a view of biasing mechanism 208 adapted for use with seal ring 200 shown in FIG. 16 .
- Seal ring 200 includes an aperture 330 and a slotted aperture 332 formed within seal ring neck portion 206 .
- Biasing mechanism 208 includes a pair of tabs 334 extending radially therefrom. Specifically, each end 216 and 220 of biasing mechanism 208 includes a tab 334 .
- One of tabs 334 includes an engagement member 336 configured to engage slotted aperture 332 .
- the tab 334 lacking engagement member 336 is positioned within aperture 330 and the tab 334 having engagement member 336 is inserted within slotted aperture 332 such that engagement member 336 slides into a retaining portion 338 of slotted aperture 332 .
- biasing mechanism 208 is positively retained within aperture 330 and slotted aperture 332 .
- seal ring 200 is substantially similar to the operation of seal ring 102 described in FIG. 3 .
- One difference between the two operations is the outward biasing force induced on seal ring 200 by biasing mechanism 208 .
- the additional outward biasing force assists to bias seal ring 200 to a larger diameter.
- the radially outward force induced by biasing mechanism 208 must be overcome prior to seal ring 200 shifting radially inward. As a result, radially inward travel of seal ring 200 is delayed until predetermined operating conditions for turbine 10 are attained.
- Each embodiment of the above-described seal ring facilitates positively retaining the biasing mechanism within the seal ring during shipment from a packing vendor to final assembly. Furthermore, the methods and apparatus described above prevent the biasing mechanism from moving during assembly. Specifically, the methods and apparatus described above prevent the biasing mechanism from falling out of the seal ring during shipment or assembly or being deformed as the seal ring is inserted into the seal assembly. As such, the methods and apparatus allow faster installation times and reduce the costs associated with seal assembly fabrication. Moreover, the above-described methods and apparatus allow for multiple cavities and biasing mechanisms and can, therefore, more equally distribute forces throughout the seal ring.
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- Combustion & Propulsion (AREA)
- Turbine Rotor Nozzle Sealing (AREA)
- Gasket Seals (AREA)
Abstract
Description
- This invention relates generally to turbines, and, more particularly, to seal ring assemblies for use with turbines.
- At least some known seal assemblies used with turbines are biased open by a spring coupled thereto. More specifically, the spring induces a radially outward biasing force against a seal ring that increases a diameter of the seal ring. As pressure is increased within the turbine, the biasing force induced by the spring must be overcome to decrease the diameter of the seal ring to facilitate preventing steam flow through the seal assembly within the turbine. Accordingly, in such sealing assemblies, radial inward travel of the seal ring is generally delayed until pre-determined operating conditions for the turbine are attained.
- At least some known seal assembly springs may be installed in the field during final assembly of the turbine. Specifically, the springs may be temporarily positioned against the seal ring using re-roundable dowels which do not provide positive retention and only retain the spring after the seal ring is installed in the packing assembly. As such the spring may fall out or be deformed during installation of the seal ring. Moreover, the seal ring can not be shipped with the spring pre-installed. Accordingly, such seal ring/spring assemblies may increase installation time, decrease quality, and increase overall costs associated with installation of the seal assembly.
- In one aspect, a method of assembling a seal assembly for a turbine engine is provided, wherein the method includes providing a seal ring having an arcuate inner ring portion, an arcuate outer ring portion, and a neck portion extending therebetween, and forming at least one recess within at least one of the outer ring portion and the neck portion. The method also includes extending a biasing mechanism across the seal ring such that the biasing mechanism is positively retained within the at least one recess.
- In another aspect, a seal assembly for a turbine engine is provided, wherein the seal assembly includes a seal ring comprising an arcuate inner ring portion, an arcuate outer ring portion, and a neck portion extending therebetween. The seal assembly also includes at least one recess formed within at least one of the seal ring outer ring portion and the seal ring neck portion, and a biasing mechanism extending chordially across the seal ring and retained within the at least one recess.
- In a further aspect, a turbine engine is provided, wherein the turbine engine includes a seal assembly configured to reduce steam leakage within the turbine engine. The seal assembly includes a seal ring comprising an arcuate inner ring portion, an arcuate outer ring portion, and a neck portion extending therebetween. The seal assembly also includes at least one recess formed within at least one of the seal ring outer ring portion and the seal ring neck portion, and a biasing mechanism extending chordially across the seal ring and retained within the at least one recess.
-
FIG. 1 is a schematic illustration of an exemplary opposed flow High Pressure (HP)/Intermediate Pressure (IP) steam turbine; -
FIG. 2 is an enlarged schematic illustration of a turbine nozzle diaphragm and a packing casing that may be used with the steam turbine shown inFIG. 1 ; -
FIG. 3 is an exemplary embodiment of a labyrinth seal assembly that may be used with the steam turbine shown inFIG. 1 ; -
FIG. 4 is an exemplary embodiment of a seal ring that may be used with the labyrinth seal assembly shown inFIG. 3 ; -
FIG. 5 is an alternative embodiment of the seal ring shown inFIG. 4 ; -
FIG. 6 is another embodiment of the seal ring shown inFIG. 4 ; -
FIG. 7 is a view of a biasing mechanism that may be used with the labyrinth seal assembly shown inFIG. 3 ; -
FIG. 8 is a view of the biasing mechanism shown inFIG. 7 and coupled within the seal ring shown inFIG. 6 ; -
FIG. 9 is a view of the biasing mechanism shown inFIG. 7 and coupled within an alternative embodiment of the seal ring shown inFIG. 4 ; -
FIG. 10 is an illustration of the biasing mechanism shown inFIG. 7 and including indicia indicative of a contact point; -
FIG. 11 is yet another embodiment of the seal ring shown inFIG. 4 and including a retaining pin; -
FIG. 12 is a front view of an another embodiment of the seal ring shown inFIG. 4 ; -
FIG. 13 is a side view of the seal ring shown inFIG. 12 ; -
FIG. 14 is a front view of yet another embodiment of the seal ring shown inFIG. 4 ; -
FIG. 15 is a side view of the seal ring shown inFIG. 14 ; -
FIG. 16 is another embodiment of the seal ring shown inFIG. 4 ; and -
FIG. 17 is a view of a biasing mechanism that may be used with seal ring shown inFIG. 16 . -
FIG. 1 is a schematic illustration of an exemplary opposed-flow steam turbine 10 including a high pressure (HP)section 12 and an intermediate pressure (IP)section 14. An outer shell orcasing 16 is divided axially into upper andlower half sections section 12 andIP section 14. Acentral section 18 ofshell 16 includes a highpressure steam inlet 20 and an intermediatepressure steam inlet 22. Withincasing 16, HPsection 12 andIP section 14 are arranged in a single bearing span supported byjournal bearings steam seal unit - An
annular section divider 42 extends radially inwardly fromcentral section 18 towards arotor shaft 60 that extends betweenHP section 12 andIP section 14. More specifically,divider 42 extends circumferentially around a portion ofrotor shaft 60 between a firstHP section nozzle 46 and a firstIP section nozzle 48. - During operation, high
pressure steam inlet 20 receives high pressure/high temperature steam from a steam source, for example, a power boiler (not shown). Steam is routed through HPsection 12 wherein work is extracted from the steam to rotaterotor shaft 60. The steamexits HP section 12 and is returned to the boiler wherein it is reheated. Reheated steam is then routed to intermediatepressure steam inlet 22 and returned toIP section 14 at a reduced pressure than steam enteringBP section 12, but at a temperature that is approximately equal to the temperature of steam entering HPsection 12. Accordingly, an operating pressure within HPsection 12 is higher than an operating pressure withinIP section 14, such that steam within HPsection 12 tends to flow towardsIP section 14 through leakage paths that may develop between HPsection 12 andIP section 14. -
FIG. 2 is an enlarged schematic illustration of an exemplaryturbine nozzle diaphragm 70 and apacking casing 72 that may be used withturbine 10. In the exemplary embodiment,nozzle diaphragm 70 is a first stage diaphragm used withhigh pressure turbine 12. Moreover, in the exemplaryembodiment packing casing 72 includes a plurality oflabyrinth seal assemblies 100 that facilitate reducing leakage from HPsection 12 toIP section 14 alongrotor shaft 60.Labyrinth seal assemblies 100 include longitudinally spaced-apart rows ofteeth 104 attached to aseal ring 102 that facilitate sealing against operating pressure differentials that may be present in a steam turbine such asturbine 10. - In operation, steam at higher pressure in HP
section 12 tends to leak through a steam path defined between firststage nozzle diaphragm 70 and packingcasing 72 toIP section 14, an area at a lower operating pressure. For example, in one embodiment, high pressure steam is admitted to HPsection 12 at approximately 1800 pounds per square inch absolute (psia), and reheat steam is admitted toIP section 14 at between approximately 300-400 psia. Accordingly, a relatively large pressure drop acrosspacking casing 72 may cause steam to leak around packingcasing 72 alongrotor shaft 60 resulting in a reduction in steam turbine efficiency. -
FIG. 3 is an exemplary embodiment of alabyrinth seal assembly 100 that may be used withturbine 10. InFIG. 3 only a portion ofrotor shaft 60 and a portion ofcasing 72 are illustrated. Furthermore, although only asingle seal ring 102 is illustrated, several such rings could be arranged in series as shown inFIG. 2 . In alternative embodiments,labyrinth seal assemblies 100 are used to facilitate sealing in other areas ofturbine 10. -
Seal ring 102 includes a plurality ofteeth 104 positioned in opposition to a plurality of rotor shaftcircumferential projections 105 extending outward fromrotor shaft 60. In the exemplary embodiment, eachcircumferential projection 105 includes radiallyouter rotor surfaces 107 positioned between a plurality of radiallyinner rotor surfaces 109. As explained above, a positive force may force fluid flow between the multiple restrictions formed by aclearance area 110 defined betweenteeth 104 androtor shaft 60. More specifically, the combination ofclearance area 110, the number, and relative sharpness, ofteeth 104, the number of rotor shaftcircumferential projections 105, and the operating conditions, including pressure and density, are factors that determine the amount of leakage flow. Alternately, other geometrical arrangements can also used to provide multiple or single leakage restrictions. For example, in an alternative embodiment,rotor portion 60 does not includeteeth 105 orsurfaces 109, but rather, is substantially planar. In another embodiment,seal ring 102 does not include a serpentine path with the rotor teeth. Further, in yet another embodiment,seal ring 102 may include a brush seal or any other suitable sealing mechanism. - Each
seal ring 102 is retained in a casing groove 112 defined incasing 72. In one embodiment, eachseal ring 102 includes a plurality of seal ring segments (not shown inFIG. 3 ) that may be positioned within casing groove 112 to facilitate ease of assembly or disassembly ofcasing 72. In the exemplary embodiment, a system of springs (not shown inFIG. 3 ) induces a force that will tend to enlarge a diameter ofseal ring 102 and a second system of springs (not shown inFIG. 3 ) may be used to counter the force induced by the weight ofseal ring 102. - Each
seal ring 102 includes aninner ring portion 114 havingteeth 104 extending from a radiallyinner surface 116, and a radiallyouter surface 130 that facilitates controllingclearance area 110 by contacting aradial surface 118 ofcasing 72. Eachseal ring 102 also includes an outer ring portion 120 that is positioned within casing groove 112. Outer ring portion 120 includes an innercircumferential surface 122 and an opposite radiallyouter surface 131. Innercircumferential surface 122 contacts anouter surface 126 of acasing groove shoulder 124 such that radial inward movement ofseal ring 102 is limited.Seal ring 102 also includes aneck portion 128 extending between seal ringinner ring portion 114 and seal ring outer ring portion 120.Casing groove shoulder 124 interacts with sealring neck portion 128 to axially locate eachseal ring 102. Sealring neck portion 128 includes acontact pressure surface 132 that contacts casinggroove shoulder 124. - One steam flow path through
labyrinth seal assembly 100 is defined fromhigh pressure region 106 tolow pressure region 108 throughclearance area 110 and betweenteeth 104 and rotor shaft surfaces 107 and 109. Steam flow is modulated as a function of radial positioning ofseal ring 102. Asseal ring 102 moves radially outward, the overall size ofclearance area 110 increases and steam flow throughclearance area 110 increases. Conversely, asseal ring 102 moves radially inward,clearance area 110 decreases and steam flow throughclearance area 110 decreases. - A second steam flow path is defined from high pressure
annular space 134 to low pressureannular space 136 through casing groove 112. Steam at a higher pressure may flow fromannular space 134 through anannular opening 140 defined betweencasing groove shoulder 124 and sealring neck portion 128. Steam is channeled throughopening 140 to ahigh pressure region 142 defined between casing groove shoulderouter surface 126 and seal ring outer ring portion ringcircumferential surface 122 before entering a casing groovehigh pressure portion 144 defined by thecasing 72 and seal ring outer ring portion 120. Steam exits casing groovehigh pressure portion 144 and enters a casing groove radiallyouter portion 148 defined between a casing groove radiallyouter surface 146 and seal ring outer portion radiallyouter surface 131. Steam may then flow to alow pressure portion 150 defined by thecasing 72 and seal ring outer ring portion 120 and to a low pressureside shoulder region 152 defined between casing groove shoulderouter surface 126 and seal ring outer ring portion innercircumferential surface 122. Steam exits low pressureside shoulder region 152 through anannular opening 154 defined betweencasing groove shoulder 124 and sealring neck portion 128, wherein the steam is discharged intoannular space 136. - Radially outward travel of
seal ring 102 is limited when seal ringouter surface 130, or any portion thereof, contacts casingradial surface 118. This position is referred to as the fully retracted position. Radially inward travel ofseal ring 102 is limited whenseal ring surface 122 contacts casinggroove shoulder surface 126. This position is referred to as the fully inserted position. Sufficient space to accommodate expected transient misalignments ofrotor shaft 60 andcasing 72, without incurring damage toteeth 104, is provided for. - At low or no load operating conditions, the weight of
seal ring 102, the confining limits ofcasing 72, frictional forces, and the forces of a plurality of biasing spring systems (not shown onFIG. 3 ) act onseal ring 102. The overall effect is thatseal ring 102 is biased to a diameter as limited by the radially outward limit of travel ofseal ring 102. - Internal pressures throughout the
turbine 10 are substantially proportional to load. As load and steam mass flow are each increased, local pressures increase in a substantially linear fashion. This relationship can be used to determine desired positions ofseal ring 102 at pre-determined turbine operating conditions. For example, as steam flow toturbine 10 is increased, steam pressure inannular space 134 and in casing groove 112 is likewise increased. The increased steam pressure exerts a radially inward force toseal ring 102 that is substantially carried by seal ringouter surfaces - The increased steam pressure in
high pressure region 106 induces increased steam flow via casing groove 112 throughannular space 134,annular opening 140,shoulder region 142, casing groovehigh pressure portion 144, casing groove radiallyouter portion 148, casing groovelow pressure portion 150,shoulder region 152, andannular opening 154 intoannular region 136. The increased steam pressure inhigh pressure region 106 also induces increased pressures in the path defined fromannular space 134 toannular space 136 via casing groove 112 as described above. The pressures in each subsequent region of the path are less than the regions preceding them. For example, the steam pressure in casing groovelow pressure portion 150 is less than the steam pressure in casing groovehigh pressure portion 144. This pressure differential induces an increased force to the right on seal ringinner ring portion 114, sealring neck portion 128 and seal ring outer ring portion 120. The increased forces on these surfaces causesseal ring 102 to move axially toward thelow pressure region 108 until seal ring neckcontact pressure surface 132 contacts casinggroove shoulder 124. When fully inserted steam flow from high pressureannular space 134 to low pressureannular space 136 via casing groove 112 is substantially prevented byseal ring 102. - The condition illustrated above causes steam pressure to induce an increased radially inward force to
surfaces seal ring 102 to overcome the previously discussed frictional forces and plurality of biasing spring sub-systems (not shown) forces. - The dimensions of
seal ring 102 and casing groove 112 are selected to facilitate optimizing theclearance 110 defined betweenteeth 104 androtor shaft 60 surface for loaded, steady state operation. -
FIG. 4 is an exemplary embodiment of aseal ring 200 that may be used withlabyrinth seal assembly 100,Seal ring 200 includes anouter ring portion 202, aninner ring portion 204, and aneck portion 206 extending therebetween.Seal ring 200 also includes abiasing mechanism 208 retained within acavity 210. In the exemplary embodiment,biasing mechanism 208 is a spring. Specifically,cavity 210 is formed withinouter ring portion 202 and includes an arcuatetop wall 212 and a pair of opposingsidewalls 214. Alternatively,cavity 210 may be formed in sealring neck portion 206,Biasing mechanism 208 extends betweensidewalls 214. Specifically afirst end 216 of biasingmechanism 208 contacts afirst side wall 218, and asecond end 220 of biasingmechanism 208 contacts asecond side wall 222. In the exemplary embodiment,biasing mechanism 208 is positively retained withincavity 210 in a friction fit created between biasing mechanism ends 216 and 220 andside walls 214. In an alternative embodiment,biasing mechanism 208 may be retained withincavity 210 by any one oft but not limited to, a tack weld, a screw, a pin, and/or glue. -
FIG. 5 is an alternative embodiment ofseal ring 200 whereinsidewalls 214 ofcavity 210 are angled. Specifically eachside wall top wall 212 such that sidewalls 218 and 222 are angled toward on another. As such a radiallyoutward portion 230 ofcavity 210 has a longer arcuate length L1 than an arcuate length L2 of a radiallyinward portion 232 ofcavity 210.Biasing mechanism 208 is positively retained within radiallyoutward portion 230 bysidewalls sidewall mechanism 208 such thatbiasing mechanism 208 is prevented from moving radially inward toward radiallyinward portion 232. In the exemplary embodiment,biasing mechanism 208 is positively retained withincavity 210 in a friction fit created between biasing mechanism ends 216 and 220 andsidewalls 214. In an alternative embodiment,biasing mechanism 208 may be retained withincavity 210 by any one of, but not limited to, a tack weld, a screw, a pin, and/or glue. -
FIG. 6 is another embodiment ofseal ring 200 whereincavity 210 includes a pair ofnotches 240. Specifically, eachnotch 240 is formed within one ofsidewalls 214 within cavity radiallyoutward portion 230. More specifically, afirst notch 242 is formed withinfirst sidewall 218 and asecond notch 244 is formed withinsecond sidewall 222.Notches 240 are each sized to retain an end of biasingmechanism 208. Specifically,first notch 242 retains biasing mechanismfirst end 216, andsecond notch 244 retains biasing mechanismsecond end 220. In the exemplary embodiment,biasing mechanism 208 is positively retained withincavity 210 in a friction fit created between biasing mechanism ends 216 and 220 andnotches biasing mechanism 208 may be retained withinnotches -
FIG. 7 is a view ofbiasing mechanism 208 including atab 250 extending axially from each biasingmechanism end FIG. 8 is a view ofbiasing mechanism 208 havingtabs 250 and coupled withinseal ring 200 shown inFIG. 6 .Tabs 250 are used to provide additional length to biasingmechanism 208 and to provide a positive engagement ofnotches Biasing mechanism 208 is positively retained withincavity 210 in a friction fit created betweentabs 250 andnotches tabs 250 may be retained withinnotches -
FIG. 9 is a view ofbiasing mechanism 208 havingtabs 250 and coupled within an alternative embodiment ofseal ring 200. Specifically, arcuatetop wall 212 ofcavity 210 includes alinear portion 260 extending from eachnotch linear portion 260 is configured to engagebiasing mechanism 208 such that bending forces within biasingmechanism 208 are distributed across the entire length ofbiasing mechanism 208 rather than being isolated attabs 250.FIG. 10 is an illustration oflocations 270 wherelinear portion 260contacts biasing mechanism 208. As described above, biasingmechanism 208 is positively retained withincavity 210 in a friction fit created betweentabs 250 andnotches tabs 250 may be retained withinnotches -
FIG. 11 is a view ofseal ring 200 including apin 280 used to retainbiasing mechanism 208 withincavity 210. In the illustrated embodiment,biasing mechanism 208 includestabs 250 engaged withnotches 240.Pin 280 is inserted throughouter ring portion 206 such thatpin 280 traverses notch 240 to facilitate retainingbiasing mechanism 208 withincavity 210. Specifically,pin 280 traverses notch 240 such thattab 250 is retained betweenpin 280 and a back surface 282 ofcavity 210. - The illustrated embodiment includes one
pin 280 retaining onetab 250. In this embodiment, thesecond tab 250 is retained withinnotch 240 by one of friction, a tack weld, or glue. Alternatively, twopins 280 are inserted throughouter ring portion 202 such that bothtabs 250 are retained betweenpins 280 and cavity back surface 282. In yet another alternative embodiment,tabs 250 include an aperture therethrough and at least onepin 280 is inserted through the aperture of at least onetab 250 aspin 280 traverses notch 240. Furthermore, in another embodiment,biasing mechanism 208 may not includetabs 250. Accordingly, at least onepin 280 is inserted through at least one end of biasingmechanism 208 aspin 280 traverses notch 240. Moreover, pin 280 may be a screw. -
FIG. 12 is a front view of an alternative embodiment ofseal ring 200 havingcavity 290 formed entirely withinouter ring portion 202; andFIG. 13 is a side view ofseal ring 200 shown inFIG. 12 . In this embodiment,cavity 290 is formed withinouter ring portion 202 such thatcavity 290 includes an arcuatetop wall 292, afront wall 294, aback wall 296, and two opposingsidewalls 298.Sidewalls 298 each include anotch 300 formed therein.Notches 300 are configured to retain ends 216 and 220 of biasingmechanism 208 such thatbiasing mechanism 208 extends acrosscavity 290.Biasing mechanism 208 is positively retained withincavity 290 in a friction fit created between biasing mechanism ends 216 and 220 andnotches 300,front wall 294, andback wall 296. Alternatively,biasing mechanism 208 may be positively retained withincavity 290 by any one of, but not limited to, a tack weld, a pin, a screw, and/or glue. Furthermore,biasing mechanism 208 may includetabs 250. Moreover, sidewalls 298 ofcavity 290 may be shaped similar tosidewalls 214 shown inFIG. 4 orFIG. 5 . -
FIG. 14 is a front view of yet another embodiment ofseal ring 200; andFIG. 15 is a side view ofseal ring 200 shown inFIG. 14 . In this embodiment,seal ring 200 does not include a cavity formed withinouter ring portion 206. Rather, this embodiment includes a pair of threadedapertures 310 formed withinneck portion 206 ofseal ring 200. Each threadedaperture 310 is configured to retain ascrew 314 therein.Biasing mechanism 208 includes a pair ofbent tabs 316 extending therefrom. Specifically, a firstbent tab 318 extends from biasing mechanismfirst end 216, and a secondbent tab 320 extends from biasing mechanismsecond end 220. Eachbent tab 316 includes afirst member 322 coupled to biasingmechanism 208, and asecond member 324 extending fromfirst member 322.Second member 324 includes an aperture extending therethrough. -
Biasing mechanism 208 is positioned againstneck portion 206 such that it is radially inward fromouter ring portion 202.Second member 324 of eachbent tab 316 is aligned with threadedaperture 310 such thatscrew 314 is received through the aperture insecond member 324 and extends through threadedaperture 310. As such,biasing mechanism 208 extends acrossneck portion 206 and is positively retained byscrews 314. -
FIG. 16 is another embodiment ofseal ring 200; andFIG. 17 is a view ofbiasing mechanism 208 adapted for use withseal ring 200 shown inFIG. 16 .Seal ring 200 includes anaperture 330 and a slottedaperture 332 formed within sealring neck portion 206.Biasing mechanism 208 includes a pair oftabs 334 extending radially therefrom. Specifically, eachend mechanism 208 includes atab 334. One oftabs 334 includes anengagement member 336 configured to engage slottedaperture 332. Thetab 334 lackingengagement member 336 is positioned withinaperture 330 and thetab 334 havingengagement member 336 is inserted within slottedaperture 332 such thatengagement member 336 slides into a retainingportion 338 of slottedaperture 332. As such,biasing mechanism 208 is positively retained withinaperture 330 and slottedaperture 332. - The operation of
seal ring 200 is substantially similar to the operation ofseal ring 102 described inFIG. 3 . One difference between the two operations is the outward biasing force induced onseal ring 200 by biasingmechanism 208. The additional outward biasing force assists to biasseal ring 200 to a larger diameter. As turbine load and steam pressures are increased, the radially outward force induced by biasingmechanism 208 must be overcome prior toseal ring 200 shifting radially inward. As a result, radially inward travel ofseal ring 200 is delayed until predetermined operating conditions forturbine 10 are attained. - Each embodiment of the above-described seal ring facilitates positively retaining the biasing mechanism within the seal ring during shipment from a packing vendor to final assembly. Furthermore, the methods and apparatus described above prevent the biasing mechanism from moving during assembly. Specifically, the methods and apparatus described above prevent the biasing mechanism from falling out of the seal ring during shipment or assembly or being deformed as the seal ring is inserted into the seal assembly. As such, the methods and apparatus allow faster installation times and reduce the costs associated with seal assembly fabrication. Moreover, the above-described methods and apparatus allow for multiple cavities and biasing mechanisms and can, therefore, more equally distribute forces throughout the seal ring.
- As used herein, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural said elements or steps, unless such exclusion is explicitly recited. Furthermore, references to “one embodiment” of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.
- Although the apparatus and methods described herein are described in the context of a seal ring for a seal assembly, it is understood that the apparatus and methods are not limited to seal rings or seal assemblies. Likewise, the seal ring components illustrated are not limited to the specific embodiments described herein, but rather, components of the seal ring can be utilized independently and separately from other components described herein.
- While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
Claims (20)
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/427,866 US7540708B2 (en) | 2006-06-30 | 2006-06-30 | Methods and apparatus to facilitate sealing in a turbine |
JP2007164507A JP5112759B2 (en) | 2006-06-30 | 2007-06-22 | Seal assembly and turbine engine for enabling sealing action in a turbine |
DE102007030135A DE102007030135A1 (en) | 2006-06-30 | 2007-06-27 | Sealing assembly for turbine has sealing ring with curved inner, outer ring regions, neck region, recess(es) in inside of outer ring and/or neck regions, bias mechanism that extends through sealing ring and is held inside recess(es) |
KR1020070064258A KR20080003266A (en) | 2006-06-30 | 2007-06-28 | Methods and apparatus to facilitate sealing in a turbine |
CN2007101262798A CN101096915B (en) | 2006-06-30 | 2007-06-29 | Methods and apparatus to facilitate sealing in a turbine |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/427,866 US7540708B2 (en) | 2006-06-30 | 2006-06-30 | Methods and apparatus to facilitate sealing in a turbine |
Publications (2)
Publication Number | Publication Date |
---|---|
US20080003100A1 true US20080003100A1 (en) | 2008-01-03 |
US7540708B2 US7540708B2 (en) | 2009-06-02 |
Family
ID=38777205
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/427,866 Expired - Fee Related US7540708B2 (en) | 2006-06-30 | 2006-06-30 | Methods and apparatus to facilitate sealing in a turbine |
Country Status (5)
Country | Link |
---|---|
US (1) | US7540708B2 (en) |
JP (1) | JP5112759B2 (en) |
KR (1) | KR20080003266A (en) |
CN (1) | CN101096915B (en) |
DE (1) | DE102007030135A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150159497A1 (en) * | 2013-12-06 | 2015-06-11 | General Electric Company | Steam turbine and methods of assembling the same |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8083236B2 (en) * | 2009-09-22 | 2011-12-27 | Hamilton Sundstrand Corporation | Staggered seal assembly |
EP2339122A1 (en) * | 2009-12-23 | 2011-06-29 | Siemens Aktiengesellschaft | Turbine with adjustable volume inlet chamber |
CN101866743A (en) * | 2010-05-31 | 2010-10-20 | 佛山市中研非晶科技股份有限公司 | Split joint method of amorphous C type magnetic cores |
US8342009B2 (en) | 2011-05-10 | 2013-01-01 | General Electric Company | Method for determining steampath efficiency of a steam turbine section with internal leakage |
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- 2007-06-27 DE DE102007030135A patent/DE102007030135A1/en not_active Withdrawn
- 2007-06-28 KR KR1020070064258A patent/KR20080003266A/en not_active Application Discontinuation
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---|---|---|---|---|
US20150159497A1 (en) * | 2013-12-06 | 2015-06-11 | General Electric Company | Steam turbine and methods of assembling the same |
US9702261B2 (en) * | 2013-12-06 | 2017-07-11 | General Electric Company | Steam turbine and methods of assembling the same |
US10774667B2 (en) | 2013-12-06 | 2020-09-15 | General Electric Company | Steam turbine and methods of assembling the same |
Also Published As
Publication number | Publication date |
---|---|
KR20080003266A (en) | 2008-01-07 |
DE102007030135A1 (en) | 2008-01-03 |
JP5112759B2 (en) | 2013-01-09 |
US7540708B2 (en) | 2009-06-02 |
JP2008014310A (en) | 2008-01-24 |
CN101096915A (en) | 2008-01-02 |
CN101096915B (en) | 2012-04-04 |
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